Sighting device for projectile-ejectors of airships.



OTTO RITTER VON EBERHARD. SIGHTING DEVICE FOR PROJYCTILE EJEcToRs 0F AlRsHlPs.

APPLlcAuoN min Mmzo. 1914.

Patented Nov. 9, 1915.

2 SHEETS-sash 1.

OTTO RITTER VON EBERHARD.

SIGHTING DEVICE FOR` PROJECTILE EJECTORS 0F AIRSHIPS. APPLICATION man JAN.20.1914.v

1,159,556, Patented Nov. 9, 1915.

2 SHEETS-SHEET 2i UNITED SAES PATENT OFFICE.

OTTO RITTER VON EBERHARD, OF BREDENEY, GERMANY, ASSIGNOR TO FRIED. KRUPP AKTIENGESELLSCHAFT, OF ESSEN-ON-THE-RUHR, GERMANY.

SIGHTING- DEVICE FOR PROJECTILE-EJECTORS 0F AIRSHIPS.

Specification of Letters Patent.

Patented Nov. 9, 1915.

Application filed January 20, 1914. Serial No. 813,294.

fo all wlw/1L it may concern.'

Be it` known that I, OTTO Birma vox EBERHARD, residing at Bredeney, Germany, a subject of the Emperor of Germany, have invented a certain new and useful Improvement in Sighting Devices for Projectile- Ejectors of Airships, of 'which the following j is a specification.

The present invention relates to a sighting device for projectile ejectors used on air vehicles, especially on flying machines, which device permits, in a new and simple manner, compensation of the deviation of the ejected projectile caused by the wind.

In the accompanying drawings, one embodiment of the invention is illustrated: Iand Figure 1 shows an elevation partly in section of the sighting device; Fig. 2, a top plan view ofFig. 1; Fig. 3 a section along the line 3-3 of Fig. 1, seen from above; and Fig. 4, a section along line 4--1 of Fig. 1, also seen from above. The following figures are in larger scale, and Fig. 5 illustrates a development of the cylindrical surface of one of the details; Fig. 6, a part of Fig. 1; Fig. 7 a section along line 7--7 of Fig. 6,

u seen from the left; Fig. 8, a. section along line 8-8 of Fig. 6, seen from above; and Fig. 9 is a diagrammatic plan view of the sighting device and individual points of the terrain beneath the air vehicle.

- In the figures, A denotes a bracket of the sighting device,4 which bracket is rigidly connected-with the stand of the air vehicle.

A, trunnion a1. which extends in vertical position when the air vehicle is in its horizontal equilibrium, is provided on the bracket. and a hood B is mounted to oscillate on this trunnion. Between the hood B and the trunnion al is inserted a self-locking worm gear, the worm@ of which carries a small hand wheel c1. see Fig. 3, and is mounted to rotate in the hood B and meshes with teeth a2 of the trunnion al. At one end of the worm shaft protruding through the hood B is fastened a drum C2, on the cylindrical surface of which are scribed two curve diagrams, each comprising a great number of curves'c3 and c4 respectively. Said surface is shown developed in Fig. 5. The purpose and the arrangement of the two curved diagrams will be more fully described below. The drum C2 is embraced at both of its end faces by two arms b1 and b2 mounted on the worm shaft and rigidly connected with each other by a rib b3. A screw spindle D, provided with a small hand wheel (Z1, is mounted to rotate in the arms b1 and b2 and relative to which the worm shaft can turn freely. slide E may be displaced in axial direction along the rib b3. 0n the slide E is provided an mdex el for the curves c3 and c4. For the purpose of reading the adjustment to be given 1n axial direction to the index, e1, which adjustment corresponds to the speed of the air vehicle, determined, for instance, in well known manner, by means of a stop watch, is provided a division d2 on the small hand wheel all together with a correspondmg mark b4 on the arm b2 ranging from 0 to 40 meter-seconds.

Mounted to swing loosely on the hood B is provided a fork having two prongs F F1 by means of a trunnion f2, the axis of which intersects the axis of the trunnion (L1 at right angles. A spindle G having a small hand wheel g1 is mounted in the prongs F F1 at right angles to the trunnion f2, and on this spindle a sleeve H is freely revoluble between the prongs F F1. The sleeve H has a circular cut h1, see Fig. 1, the axis of its curvature being parallel to the axis of the spindle G. In this cuit is guided a sight bar J, 4which is correspondingly curved along a portion of its length. The curved portion of the sight bar is provided with teeth l meshing with a pinion g2, see Figs.

lum weight H3 is suspended from the sleeve' H, the bar being rigidly connhected therewith so that the sleeve H at each adjust! ment, which the sight bar J` is given by means of the gears g2 1 relative to the sleeve, will be retained in a position in which the axis of the bar h2 remains perpendicular, during the oscillation of the air ship. At the upper end of the sight bar J is situated a semicircular direction plate 2 which is rigidly connected therewith and the plane of the axis of curvature of this plate is parallel with the curved portion of the sight bar. A slide K is adjustable along the circumference of the direction plate 2'? upon which slide an arm M is mounted to revolve by means of a radially directed trunnion m1, which arm terminates atl its free end in a guide sleeve m`, see particularly Figs. G, 7 and S. In this sleeve m2 is 'carried a square bolt N, the central longitudinal axis' of Which runs through the intersecting point of the trunnion m1 and the axis of curvature of the semicircular direction plate 2. At the end thereofV nearest the .axis vof curvature of the direction plate 2,

.-hafnd. wheel P1, which is revolubly but not displaceably mounted on the sleeve 'm2, is provided.- for displacing in the axial direction the bolt N` with the notchV nl, vand this screw P is in mesh with internal threads provided in the axial boring of the bolt N.v g vOn the circumference of the small hand 4Wheel P1 is arranged a scale p2 corresponding to the strength of thevvind, Whichscale extends in both directions from the zero fpoint p8, see Figs. 2 and 7 and is provided .with similar numbers. The position of the -zero point p3 has been so selected that it registers with. the reading mark m4, providedfor the scale p2 on the sleeve m2, see

Fig. 2, when thevnotch n.1 is situated in the ,l

axis of 'curvature of the direction plate 52. lThe directionl which the sight line possesses with the above described adjustment of the notch, will, for thesakeaoff shortness, in the following be called the f main direction of the sight line. For determining the side direction of the bolt N, carrying the notch fnl, serves a reading'',markc2 situated on the slide K and anangular divisonf* arranged at the ,outer edge 'of'the direction scale '52 which angular scalevcoi'nprise's angles from to 180 being uniforml numbered with numerals-from .0 to 16. T e position ofthe zero point has been'so selected that it registers wththemarkl, whenthe central 1011-'A 'gitud'inal' axis of the bolt W at right angles with the' axisfof curvature of the por- .tion f, thev sight-bar'J .which is curved if which is intended for ldetermining the the arch of acircle'. =4 :.@n this portion 'efjthe forms. ,with the .directiQn of travel.

sightbar is 'lastlyprovided an: angular scale 4 angle of ejection, ,thisxneais 'that'v angle which main direction ."of'th'e sight line'4 must jlrni with the axis 'oftflle si'ghtbar 71?-, in orde" thatthe'.projcctile',"siip3osed lto ,be immune' tothe action o fjthe Win l may :hit 'a certain point in fthe terr'l fwhifh projectile has been'y ejected attliejlmoment th'elfmain dertien of ih@ sieh-mme ,Grossen pointof terrain. For readingA the scale i v a mark h4 is provided on the sleeve H.

` been Vcorresp'o'ndingly adjuste In the diagrammatic plan view, Fig. 9, it has been supposed `that the sight bar J has i "."by means of the gears g2 i so that the sight line is inclined as seen from below and in front, and that the direction plate 2 hasa correspondingly inclined position. The point o denotes the projection of the axis of the-trunnion a1,

' the point g, .the projection of the front sight point determined by the conev 713,, and the point r the projection of the rear sight point determined by the notch nl, when the notch nl is adjusted in the axisoi curvature of thel direction plate 2 as for instance has `been 'sho-Wn in Figs. 2 and 8;A

When the air vehicle moves, influenced by- Speed failing vin the direction of the iongi-i tudinal axis of the air vehicle, and the line a-b the Wind speed rw, the line o-b will Which will be denoted by the character v Furthermore-.in the triangle vo a b the angle `b ola is equal tothe angle denoting the deaviation` in the direction lof travel from the longitudinal axis of the air vehicle. Supposing now that the sighting device, by means ofI turning the small hand Wheel c1 so as to revolve the hood B around the. trunnon'val, has been swung sidewise from its middle'position represented in Fig. 2, so far that the projection g-'w of the main direction of the sight line falls in the direction of travel, so must the angle 'in which the hood B has been turned be lequal to and threfore the turning angle ofthe drum C2 *"proportional t It Will be`i evident from consequently represent the speed of travel the triangle wai-b that the value'w of the Windspeed, under the supposition, that the actual speed o--a were constant, "1s only la ffunction of the values c and sothat if the angle'andthe value v are given, the value 'w` is also determined; the angle being determined by the adjustment of the sighting de- 'vice-'into the direction of travel, and the vv-value v determined, in Well knowmmanner, .by a stopwatch, for instance. The same also 'appliestothe angle Which the Wind speed jfposing thatthe angle is to be measured by vthat'al'igle through which the side -b of the".triangle'ha's to be'turned around the vertex b in. clockwise direction in order to bring" it the vdirection'of the side o-b of 'the trianglefit'will follow that the angle 4Will be vnieasured'by the angle o b a of the triangle incase that the direction of travel f dev-iates yto the left from the direction ofthe longitudinal axis of the vehicle, as has been the surface line C5, in a suitably selected scale, which naturally must correspond to the division d2, serving to determine the axial adjustment of the mark e1; and let it furthermore besupposed that the angle is scribed in such a sca-leon a line c run- 'ning circumferentially through the zeropolnt of the surface line c5, that by a turning of the drum C2 the revolving angle of the hood B, measured from the middle position, will always be the same as the angle produced by the distance of the mark el from the surface line c5, measured circumferentially. If now in the cordinate system formed by the line c and c", the ratio between the value fw, v and is graphically represented by curves, so that each curve represents a constant value of the wind velocity w and cordinates for each curve point represent corresponding values 'v and curves c3 will be obtained which denote wind velocities of 10, 20, andi-10 meter-seconds as represented in Fig. 5. If in similar inanner the ratio between the values v and are laid out, curves c4 will be obtained. For angles which only range between 0 and 180, is then selected the same unit on which is based the division 4 of the direction plate 2, So that the angle 6:0 expresses the scale number 0, and the angle (5:180o the scale number 16. The curves c, in Fig. 5, all denote thefvalues for all the Whole numbers ranging from 0 to 16.

The operation of the described sighting device is as follows: The sighting device is, if necessary, first adjusted so that the notch nl is situated in its zero position, see Figs. 2 and 8, represented' by the point r in Fig. 9. The sight line is thereupon directed against the target z, Fig. 9, by turning the small hand Wheels g1 and 01, and retained in the` direction of the targetby continued turning of the small hand Wheels g1 and c1.l The air vehicle is similarly steered in such a direction that the direction of travel runs through the target. If this is the case, the siglitdirection of the sighting device need novfurther change by turning the small hand wheel c1, because the vehicle now moves in such a manner that the straight line o-fr-g continually coincides with the straight line The drum C2 is now adjusted by turning thesmall hand wheel c1 to correspond to the angle In further advancement in the course it is not necessary to retain the target iI1` the sight line. By the use,

for instance, of a stop watcli,'the traveling speed "2.' is now determined, and the sight bar J adjusted ytQ-tlfe ejecting angle correvision d2 under coperation ofthe mark b* by turning the small hand wheel (lf.

The mark e1 receives through this adjustment the axial displacement relative to the drum C2, which corresponds to the traveling speed v. `Tl1e value of angle which the wind direction forms with the travellng direction will, now be shown through the position which the mark el takes with regard to the curve 0*,'fand the value w of the wind speed will be shown through the position of the mark e1 relative tothe curve 03,. v

By now' turning the small hand` wheel p1, the bolt N carrying the notch nl will bedisplaced in the axial direction until thev mark m4, see Fig. 21'egisters Withthe division line of the division value lw read oii the drum C2; and this displacement takes place, according to whether the direction of travel deviates to left or right from the longitudinal axis of the vessel, either toward the outer edge of the direction plate 2 or in the opposite direction.

p2 which corresponds to .the

The slide K will furthermore be so adjusted bolt axis were parallelto this plane. iIn

consequence of the inclination which the directionplate 2 has obtained through the adjustment of the ejecting angle this will, howevr,.not actually occur. As, however, the inclination of the direction plate is usually comparatively sinall, it can, a's a rule', be supposed that ther projection of the axis of the bolt N is'with suilicient exactitude parallel to the .Wind direction.

-1 `The hereabove outlined manner .of measuring the anglel has fthe advantage over {measuringof the prior art that the division z" can be used both for deviations of the traveling direction to right and left of the longitudinal axis of the vessel. Lastly the arm M has to bev turned so far around the axis of-'the trunnion m1. untilthe mark m3 representing the altitude of the vessel registers with the division line of the division lul. The projection of the rear sighting point determined bythe notch nl after making the above mentioned adjustments as denoted by s. Fig. 9. In the revolution of the arm M around the axis of the trunnion mi it always relates to comparatively small angles of revolution. .This has therefore very little intain value corresponding to the strength and the altitude of the vessel.

The projection of the sight line now falls in the straight line s-g. The point at which the sight line crosses the terrain is denoted by t in Fig. 9. All the dimensions relating vto the sighting device are for the sake of clear-ness in Fig. 9, represented in a considy erably larger scale than the dimensions relating to the terrain; the ratio between the lines s--g and g--t is therefore in reality much smaller than shown in the drawing. The point t moves in a straight line t-u which is parallel to the traveling line denoted by the points o, b, r, g, e and which line passes to the left of the target z with the supposed wind direction in Fig. 9.

After the completion of all above named adjustments of the notch nl, the vessel will now be steered so far to the side, that the point t follows in the original traveling line o-b--r-g-z when care has to be taken that the vessel again moves parallel to the original traveling line when the point t has attained the above namedr position. This will be known from the fact that the direction in which the point t is now moving runs through the target a. ,v The position which the sighting device after the above mentioned side movement of the vessel has at a vcertain moment, is in Fig. 9 denoted by I and shown with dotted lines. The new position of the points gI r s and t are correspondingly represented With g1, 111, s1 and The traveling line coincides now with the straight line r1 q1 which is parallel with the original traveling line o-b-r-g--a The point t1 during further advancement in the course along the line o-b-r-g-z now approaches the target z. As soon as the point t1 coincides with the target z, that means as soon as the sighting line runs through the target, the projectile will be ejected. The position which the sighting device has at this moment, is denoted by )II and again shown by dotted lines in the iigure. The position4 ofthe points g, 7' and s corresponding to this position are correspondingly represented with g2, r2 and s2.

The point which the projectile hits if it were immune from the action' of the wind, will now be represented by This point is situated in the traveling line rl-gl-/rg-QZ and coincideswith the point wgherein the main direction of the sight line intersects With the terrain, the main direction being projected in the straight line rz-gz. The line -z must now be parallel to the line r2-a2 and consequently also approximately parallel with the wind direction. rl`he length of the line .az-z depends substantially only on the length of the line l7'2-82 or 1--8 and the altitude of the vessel. As noW the length of the line r-s is dependent on the strength of the wind andalso on the altitude, it can vbe so arranged, through suitable selection of the division p2 corresponding to the strength of the wind and the direction lol corresponding to the altitude, that the line -z obtains a certain predetermined value for each strength of the wind and each altitude. The influence that the jwind has on theV ejected projectile now, causes it not tovstrike the poi-nt but a point which lies in the direction of the wind,

that means approximately in' the direction t. m--a in a definite distance from the point'w. The length of this line'depends principally on the strength of the wind and the altitude.

If therefore. the divisions p2 and .:1 are so selected that the line m-.a f strength of Wind and of 'certain altitude 'is equal to the length of the line Which the actual striking point. is advanced from the point with the same strength of Wind and altitude, this striking point will `fall almost exactly on the target. A g

As has already been described the turning of the arm M around the axis of the trunnion m1 corresponding to the altitude is al-ways comparatively small. It will therefore be sufiicient in most cases if the arm M has a Xed position corresponding to acerin transverse direction relative to the sight bar.

2. A sighting device for air vehicles having a. sight bar, and a guide therefor, a bracket with an upright trunnion on which said guide is mounted to oscillate in the side direction, means for setting said sight bar relative tothe ejecting angle of the jectile and. other means for displacing the sight line in transverse direction relative to the sight bar, a reading device adjustable relative to different valuesof the traveling speed, whereby, on adjusting said device for a given traveling speed said device will indicate the values of the wind strength and Wind direction corresponding to each value of the turning angle of said guide in the side direction around said upright axis; the turning angle of saidl guide out of its middle position being equal to the angle or a certain ing a sight bar,

45 to the sight bar,

10 line in transverse direction relative to the sight bar, said sight bar being provided With two sighting points of which one is adjustable relative to the sight bar.

4. A sighting device for air vehicles havand a guide therefor,a bracket with an upright trunnion on which said guide is mounted to oscillate in the side direction, means for setting said sight bar relative to the ejecting angle of the projectile and other means for displacing the sight line in transverse direction relative to the vsight bar, a reading device adjustable relative to different values ofthe traveling speed, whereby, on adjusting said device for a given traveling speed saidfdevice Willsindicate the values of the wind strength and wind direction corresponding to eachvalue of the turning angle of said guide 1n the slde direction around said upright axis; the

turning angle of said guide out of its middle position being equal to the angle formed by the longitudinal axis ofl the vessel ivith the direction of travel; said sight bar being provided with two sighting points, and one of said sighting points being adjustable relative to the sight bar.

5. A sighting device for air vehicles having a sight bar, and a guide therefor, a bracket with an upright trunnion on which said guide is mounted to oscillate in the side direction, means for setting said sight bar relative to the ejecting anglel of the projectile and other means for displacing the sight line in transverse direction relative said sight bar being provided with two sighting points, one offsaid points being adjustable relative tothe sight bar, and means for adjusting said movable point sidewise corresponding to the Wind direction and radiallv corresponding to the wind strength.

6. A sighting device for air vehicles having a sight bar, and a guide therefor, a bracket with an upright trunnion on which said guide is mounted to oscillate in the side direction, means for setting saidsight bar relative to the ejecting angle of the projectile and other means for displacing the sight line in transverse direction relative to the sight bar, a reading device adjustable relative to different values of the traveling speed, whereby, on adjusting said device for a given traveling speed said device will indicate the values of the Wind strength and Wind direction crrespondingvto each value of the turnvided with ing angle of said guide in the side direct around said upright axis; the turning ax 'of said guide out of its middle position ing equal vto the angle formed'by the lor tudinal axis of the vessel with the directioi travel; said sight bar being provided v two sighting points, and one of said sight points being adjustable relative to the si, bar, and means for adjusting said mova point sidewise corresponding to the W; direction and radially corresponding to Wind strength.V

7. A sighting device for air vehicles h: ing a sight bar, and' a guide therefor. bracket With an upright trunnion on Wh. said guide is mounted 'to oscillate in the s: direction, means for setting said sight l relative tofthe ejecting angle of the p. jectile and other 'means for displacing 1 sight line in 'transverse direction relatf tothe sight bar, said sight bar being p: y two-sighting points, one of s: pointsbeing'adjustable relative to -the sig ar, a carrierfor said movable sighti point, and a direction bar, said carrier being on' said direction Wind direction;

8. A sighting device for air vehicles ha ing a sight bar, and a guide therefor, bracket with an `upright trunnion on Whi 4said guide`is mounted to oscillate in the 'si irection,lmeans for settingsaid sight b relativeto the ejecting angle of the` pr jectile and. other means for displacing tl sight line in transverse direction relative the sight bar, said sight bar being providi with two sighting points, one ofsaid-poin being adjustable relative to thef'sight ba a revoluble spindle carrying said movab sighting point and a supportfor said spi] dle', 'a'direction plate on said sight vbar co1 structed to guide said support, vsaid suppo: being displaceable sidewise on said dire plate on said sig adjustable sidew; plate correspondingfto t tion plate corresponding to the Wind' dire bar relative to the,` ejecting angle ofth projectile and other meansfor` displacin, the sight line in transverse direction rela tive to the sight bar, a4 reading device ad justable relative todilferent values of th traveling speed, whereby, on adjusting sai| device for a given traveling speed said de vice Will indicate the values of the wim strength and W'ind direction corresponding to each value of the turning angle ofsaif guide in the 'side direction around said up right axis; the turning angleof said guidv out of its middle position being equal" t( 

